1. Field of the Invention
This invention relates to an electric motor-driven rope pull hoist, useful for operating motor vehicle windows, doors, sliding roofs and the like. More particularly, the hoist has a closed rope loop which is driven by a rope drum. A permanent magnet electric motor having a flat housing and a motor shaft end which extends into an adjacent gear box and, active through a worm, turns a worm wheel connected to the rope drum.
2. Description of the Prior Art
The use of motor-driven rope pull window raisers in motor vehicles for transmitting power from the driven shaft of an electric motor to a worm wheel, via a worm, is described in German Auslegeschrift No. 17 08 310. The worm and worm wheel are housed in a gear box and the worm wheel shaft protrudes out of the gear box to form the axis of a crank bolt carrying a small gear which meshes with a large gear supporting the rope drum. In motor-driven window raisers according to the state of the art the motor is flange mounted laterally to this intermediate gear arrangement.
In one known drive motor for a window operating mechanism in motor vehicles, a permanent-magnet DC motor is disposed in a flat, tightly closed housing, and has subsequent gearing. The magnetic return path for the motor comprises a U-shaped crossbar having free leg ends with faces resting against one side of an additional return path lamination. The other side of the lamination is adjoined by a cast aluminum gear box. The motor part of the drive is sealed by a thermoplastic cover over the return path crossbar and the outer edge of the return path lamination. The motor shaft, which extends through an opening in the return path lamination into the gear box and is provided there with a worm wheel, is mounted in sintered iron bearing cups which are fastened, on the one hand, to a bent yoke connecting the legs of the return path crossbar and, on the other hand, so as to rest directly against the gear box.
It is an object of the present invention to provide a rope pull hoist of great efficiency and, at the same time, great compactness, which can be made with simple production and assembly means.